TrueType Typography
Parametric TrueType Fonts

Introduction
Type designers might be excused for being wary of imaginative computer programmers who learn a bit about type design. For several such computer people have decided that defining a separate bitmap or outline for each character is a shallow means of representing fonts digitally. They have declared that fonts can not only be classified by the weight of their strokes, the serif style, the x-height and other proportions, but they have added the big step of enabling fonts to be regenerated from lists of such parameters. For legal purposes these "synthetic" fonts are sometimes described with language such as "compatible with...", but the motivation is clear: these fonts are claiming near-equal status as originals...

The fine typographer hopes that readers (at least discerning ones) will reject computer-generated fonts, just as the discerning listener derides electronic music, synthesized renditions of favourite pieces above all.

METAFONT
Donald Knuth went a step further with METAFONT. Using its algebraic programming language, one can write code that acts on parameters, completely defining a whole family of fonts (a "clan", to use Sumner Stone's term). All the "Computer Modern" fonts in Knuths's widely used TeX typesetting system were created with METAFONT. A single well-written Metafont program generates many font styles, just by changing key variables (i.e. parameters).

What about TrueType?
A couple of parametric font systems that relate particularly to TrueType are described below. Sadly they are both unavailable now, after the companies that created them were bought out.



ElseWare: FontWorks, InfiniFont and PANOSE 2.0

FontWorks is a parametric font generation system. Using major extensions to the PANOSE concept [the system devised by ElseWare for stylistic font classification and matching] it enabled the re-creation of outline fonts from their parametric descriptions. These sets of parameters were convenently small, so you could afford to have the complete set of 150 fonts installed. When the user selected an ElseWare font in a document, a "synthetic" TrueType font was generated and kept in memory. The first request would take a few seconds to complete, but after that the system was as efficient as standard TrueType. FontWorks ran on Windows 3.1x only.

Although not available any more to the public as FontWorks, the same "InfiniFont" technology for font synthesis is now part of Hewlett-Packard's PCL6 printer language (and may soon become important to Web font specification).

FontWorks was ultimately of limited interest to the typographer as it gave no control of the parameters to the user: the focus was on font compression. It's interesting to note how close compression and parametrization (i.e. understanding the principles) of type are.

ElseWare was acquired by Hewlett-Packard in late 1995: see the press release.

  • PANOSE White Paper from Hewlett-Packard, describes how PANOSE 2.0 parametrizes fonts for both classification and synthetic regeneration.

  • PANOSE and InfiniFont are described at HP's font site. There's a searchable PANOSE database under construction, as well as other goodies.

  • The InfiniFont ideas were presented at the RIDT '94 Conference in Darmstadt, Germany, and published in the proceedings: "Electronic Publishing: Origination, Dissemination and Design" (Vol.6 No. 3) ISBN 0-471-94823-3.



Ares FontChameleon

FontChameleon (created by the same team that brought us FontMonger and Letraset FontStudio) was an extremely powerful font manipulation program. Its power resulted from taking direct control of outline editing away from the user. Using a new way of representing fonts, where each character was defined as a set of "difference descriptors" from a generic outline, Ares created close approximations of 150 well-known fonts. These all shipped with Version 1.0 - which cost around $300. Using on-screen slider controls, you could adjust the weight, width, x-height, slant and tracking of these fonts, as well as blending one font into another!

In general, all characters of all fonts were defined in terms of repositionings of the same set of control points (though letters such as 'a' and 'g' had more than one point-set for obvious reasons). Exploiting stylistic consistency within a font, these repositionings could be parametrized so that each font was expressible as a 2K parameter set - compared with 40K to 60K for standard font formats. So this new power could save 95% of your fonts' disk space too.

A simple use of FontChameleon's blend feature would be to interpolate between Helvetica Regular and Helvetica Bold. With my second try on the program, I tried a more crazy use: interpolating between Garamond and Futura. Wow! All the grunge fonts you'll ever need, and then some! (Ernie Brock, one of its developers, told me how ideal TrueType was for much of the blending. You could use its interpolated on-curve points to vary a corner from sharp to curved: just bring two consecutive off-curve points together, and... we have a corner point.)

The first version could not handle true italic fonts (the stylistic variations are difficult to unify parametrically), but this was solved in Version 1.5. This also added more stylistic variations: you could independently control the heights of ascenders, descenders, capitals and numerals. The program came with fewer fonts (perhaps they rightly started to worry about copyright infringements), but the price was reduced to $55 - in Mac and Windows versions.

Now that Ares is owned by Adobe, and bearing in mind the potential personality clash with multiple masters, FontChameleon (along with all of Ares' other font products) has been discontinued.

John Spragens of InfoWorld reviewed FontChameleon 1.5 in April 1995: Font generator FontChameleon makes custom fonts easy work - "FontChameleon didn't make me a master typographer, but it did allow me to create a reasonably attractive, custom face with an ease no other program can match. Opinion: Buy it!"



More Parametric Font references

LiveType
An amazing working system for parametric control over type redesign, by Ariel Shamir and Ari Rappoport of the Hebrew University of Jerusalem. The website has some excellent animations showing LiveType in action. Also described is ParamTT, a program that automatically extracts the "features" that are controlled parametrically by LiveType.

METAFONT online documents
A collection of TeX documents, including...

The METAFONTbook [TeX format]
The essential book on METAFONT by its creator Donald E. Knuth, Computers & Typesetting Volume C, Addison-Wesley (1986), ISBN 0-201-13445-4.

Metafont, Metamathematics, and Metaphysics
Article by Douglas Hofstadter (1982). Subtitled: "Comments on Donald Knuth's article The Concept of a Meta-Font". Originally published in Visible Language, it appears with a new postscript as chapter 13 in Metamagical Themas by Douglas R. Hofstadter (Basic Books, 1985). Hofstadter firmly rejects the notion, inherent in all existing parametric font generation systems, of any fundamental distinction between 'book' and 'display' fonts: "It is quite naïve to think that low wildness means 'the same old book-face knobs are twiddled' no matter who's doing it, whereas high wildness involves an open-ended set of concepts."

Generation of Roman Printed Fonts
Frequently cited Ph.D. thesis by Philippe Coueignoux, MIT (1975).

"abcdefg"
[a better constraint driven environment for font generation] by Debra Adams, Xerox PARC (1987) in the proceedings of the 1989 Raster Imaging and Digital Typography conference, pp. 54-70. Describes an experimental system that automates the generation of letters in a font from 4 'control' characters (o, h, p and v). Cited in Intelligent Graphics by Henry Lieberman of the Visible Language Workshop, MIT Media Lab.

Letter Spirit
Not exactly parametric type, but here seems the best place to mention this fascinating project by Gary McGraw, under the guidance of Douglas Hofstadter. It's "an attempt to model central aspects of human creativity on a computer", using analogy-modelling techniques the group calls fluid concepts. The domain they've chosen for these experiments is the automated design of "grid fonts", letters as patterns on a criss-cross grid with diagonals allowed. The whole Ph.D. thesis is online. Chapter 10 of Hofstadter's book, Fluid Concepts and Creative Analogies (Basic Books, 1995) is devoted to Letter Spirit.


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